COVID-19 studies are our top priority. For all other trials, there is a 4-week delay in processing a trial submitted to the ANZCTR and additional delays for updates of registered trials. We appreciate your patience.

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers
Trial details imported from

For full trial details, please see the original record at

Registration number
Ethics application status
Date submitted
Date registered
Date last updated

Titles & IDs
Public title
Desensitising Celiac Disease Patients With the Human Hookworm
Scientific title
Combining Necator Americanus With Trace Gluten to Restore Tolerance in Coeliac Disease: a Pilot Clinical and a Detailed in Vitro Immunological Study.
Secondary ID [1] 0 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Celiac Disease 0 0
Condition category
Condition code
Inflammatory and Immune System 0 0 0 0
Autoimmune diseases
Oral and Gastrointestinal 0 0 0 0
Other diseases of the mouth, teeth, oesophagus, digestive system including liver and colon
Human Genetics and Inherited Disorders 0 0 0 0
Other human genetics and inherited disorders

Study type
Description of intervention(s) / exposure
Other interventions - Necator americanus
Other interventions - Necator americanus

Experimental: Necator americanus, gluten challenge - Single arm, vertical.

Other interventions: Necator americanus
Previously inoculated subjects will be further inoculated as previously undertaken with 20 3rd stage infective Na larvae (10 + 10 over 4 weeks). Four weeks after the 2nd inoculation, each participant will receive a micro-dose of gluten (10 mg daily) as pasta for 8 weeks, to be followed by a low-dose of gluten (50 mg daily) for 8 weeks. After this, a detailed assessment involving upper endoscopy and duodenal biopsy will be performed before deciding on an individual case basis that it is safe for the participant to proceed to challenge. A gluten challenge of 1 G (15-20 G of pasta or a ½ slice of standard white bread) twice weekly for 12 weeks will commence.

Other interventions: Necator americanus
After completion of the previously planned challenge, volunteers will be invited to extend the gluten challenge. The extension is for 4 weeks total. The gluten challenge is stepwise: gluten 10 mg daily for one week, 50 mg daily for one week and finally 3 grams daily for 2 weeks. The outcome measure is serum tissue transglutaminase to be compared before and after the intervention.

Intervention code [1] 0 0
Other interventions
Comparator / control treatment
Control group

Primary outcome [1] 0 0
Duodenal Villus Height:Crypt Depth - Biopsies were fixed in neutral buffered formalin, processed and carefully orientated and embedded in paraffin wax. Sections (3 µm) were stained with H&E. Slides from both time-points were de-identified, shuffled and graded by Dr John Croese after which results from poorly orientated slides were verified by Dr Andrew Clouston. The Vh:Cd ratios were measured on 5 randomly selected well-orientated sites. The null hypothesis is that hookworm infection will not protect against mucosal damage following 12-week exposure to gluten in celiac disease.
Timepoint [1] 0 0
Week -24 to -36
Secondary outcome [1] 0 0
Intraepithelial Lymphocyte Count - Biopsies were fixed in neutral buffered formalin, processed and carefully orientated and embedded in paraffin wax. Sections (3 µm) were stained with anti-CD3. All slides were de-identified and graded by Dr John Croese. The IEL percentages were measured on 2 or more randomly selected well-orientated villi. The null hypothesis is that hookworm infection will not protect against mucosal IEL influx following 12-week exposure to gluten in celiac disease.
Timepoint [1] 0 0
Week-24 and -36
Secondary outcome [2] 0 0
Number of Participants With 2 Points Increase in Marsh Score Post GC-1g - The Marsh score is a defined but qualitative assessment assigned a value to allow for comparison. The scores were evaluated by consensus between the primary (chief) investigator and the study pathologist. The Marsh score was graded 0, 1, 2, 3A (assigned-4), 3B (-5) and 3C (-6); rage 1-6 with normal=0 and severe inflammation=6. Because the scoring is vulnerable to artefact, only a 2-point shift was regarded as a significant intra-individual change. The scores were graded after week-36 on biopsies de-identified shuffled. An upward shift was interpreted to reflect a significant worsening of gluten-associated inflammation. The comparison reported evaluated changes from baseline (week-24) to post-low-dose gluten challenge (week-24; GC-1g). The objective for using the Marsh score was to identify individuals who might have experienced a severe worsening in pathology due to GC-1g that might not be reflected in the Vh:Cd group analysis.
Timepoint [2] 0 0
Longitudinal change between week-24 and week-36
Secondary outcome [3] 0 0
Serum Anti-tissue Transglutaminase Antibodies Measured as International Units/mL (IU/mL) - The trial was extended with pre-trial and mid-trial anti-tTG antibody levels used to compare with the post-trial levels. Anti-tTG is a serological measure of tissue transglutaminase-2 antibodies. In active celiac disease, levels are increased. In treated disease, levels are low (normal cut-off was <15 IU/mL). A significant increase compared to baseline in tTG can be expected 2 weeks after consuming 3g of gluten daily for 2 weeks in people with celiac disease who have been maintaining a gluten-free diet, but who are not taking other treatment.
Timepoint [3] 0 0
Anti-tTG IU/mL levels pre-trial, mid-trial and after 3 gram/day gluten challenge

Key inclusion criteria
- Previously enrolled adults who received an experimental hookworm infection with diet
treated celiac disease.
Minimum age
18 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
- Immune suppressive therapies

Study design
Purpose of the study
Allocation to intervention
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

The people assessing the outcomes
Intervention assignment
Single group
Other design features
Phase 1/Phase 2
Type of endpoint(s)
Statistical methods / analysis

Recruitment status
Data analysis
Reason for early stopping/withdrawal
Other reasons
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment hospital [1] 0 0
Prince Charles Hospital - Chermside
Recruitment postcode(s) [1] 0 0
4032 - Chermside

Funding & Sponsors
Primary sponsor type
The Prince Charles Hospital
Other collaborator category [1] 0 0
Name [1] 0 0
National Health and Medical Research Council, Australia
Address [1] 0 0
Country [1] 0 0

Ethics approval
Ethics application status

Brief summary
We have established that the hookworm Necator americanus (Na) dramatically alters the local
and systemic immune landscape of the infected human host. Consistent with the principle of
desensitisation, diet managed celiac disease subjects previously infected by us with Na will
be invited to receive small incremental doses of gluten as pasta (3-25 mm straw of spaghetti)
over 16 weeks. Each participant will then be carefully re-assessed to determine if it is
appropriate to undertake a 12-week gluten challenge.
Trial website
Trial related presentations / publications
Daveson AJ, Jones DM, Gaze S, McSorley H, Clouston A, Pascoe A, Cooke S, Speare R, Macdonald GA, Anderson R, McCarthy JS, Loukas A, Croese J. Effect of hookworm infection on wheat challenge in celiac disease--a randomised double-blinded placebo controlled trial. PLoS One. 2011 Mar 8;6(3):e17366. doi: 10.1371/journal.pone.0017366.
Public notes

Principal investigator
Name 0 0
John Croese, MD
Address 0 0
The Prince Charles Hospital, Centre for Biodiscovery and Molecular Development of Therapeutics
Country 0 0
Phone 0 0
Fax 0 0
Email 0 0
Contact person for public queries
Name 0 0
Address 0 0
Country 0 0
Phone 0 0
Fax 0 0
Email 0 0
Contact person for scientific queries

Summary results
Other publications